Error: The server returned an invalid or unrecognized response.

Error Message

When trying to create a ASP.Net Web Application from Visual Studio.Net, the following error may be returned:

The web server reported the following error when attempting to create or open the Web project located at the following URL: 'http://localhost......'. 'The server returned an invalid or unrecognized response.'


Visual Studio.Net may have been installed before IIS (Internet Information Systems). The correct order of installation should be:

1. Operating System
2. IIS
3. Visual Studio .Net
4. ArcGIS Server

Solution or Workaround

The following steps will register IIS with Visual Studio .Net if IIS was installed after Visual Studio .Net.

  1. Start the Visual Studio Command Prompt by navigating to Start > Microsoft Visual Studio .Net 2003 > Visual Studio .Net tools > Visual Studio 2003 Command Prompt.
  2. At the command prompt, type 'aspnet_regiis -i' and then press return to run this command. It may take a few minutes to complete.